Compile GraalVM images with -march=compatibility.

Author: fniephaus

sdk/mx.sdk/mx_sdk_vm_impl.py

@@ -1255,6 +1255,7 @@ def contents(self):
             image_config = self.subject.image_config
             build_args = [
                 '--no-fallback',
+                '-march=compatibility',  # Target maximum portability of all GraalVM images.
                 '-H:+AssertInitializationSpecifiedForAllClasses',
                 '-H:+EnforceMaxRuntimeCompileMethods',
                 '-Dorg.graalvm.version={}'.format(_suite.release_version()),